Two stroke diesel engine

Abstract

In a two stroke diesel engine which comprises a combustion chamber formed by a cylinder, piston head and base of the cylinder head, a cavity formed on the base of the cylinder head facing the combustion chamber, intake valves fitted to the cylinder head facing the cavity, a fuel injection valve fitted to the cylinder head facing the cavity, and exhaust valves fitted to the base of the cylinder head, fresh gas entering from the intake valves flows into the combustion chamber via the cavity in a scavenging step, and effectively sweeps out burnt gas. Further, as fuel and air are mixed in the cavity near the top dead center of the piston stroke, and this gas mixture is ejected together with the flame that ignited in the cavity into the combustion chamber as the piston descends, combustion in the chamber takes place efficiently.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A two stroke diesel engine comprising: a cylinder with a cylinder wall and an open end;   a cylinder head having a flat base which closes the open end of said cylinder;   a piston accommodated in said cylinder such that it is free to slide in said cylinder between its top dead center and bottom dead center, said piston having a flat piston head disposed parallel to the base of said cylinder head;   a combustion chamber formed in said cylinder by said piston head and the base of said cylinder head, said combustion chamber having a minimum capacity when said piston is at the top dead center,   a cavity formed in said cylinder head with an opening in the base of said cylinder head, said cavity having a roof with a flat surface parallel to the base of said cylinder head, an extension wall continuous with said cylinder wall and a first pair of cylindrical walls facing said extension wall, said first pair of cylindrical walls defining a common edge wherein said walls intersect and a lower edge disposed at the opening of said cavity;   a pair of intake valves and seats therefor provided in said cylinder head facing said cavity, said intake valve seats forming a part of the flat surface of said cavity roof, each of said intake valves having a rim disposed equidistantly from one of said cylindrical walls,   a fuel injection valve mounted in said extension wall and disposed substantially horizontally in front of and perpendicular to the common edge of said first pair of cylindrical walls, and   exhaust valves provided in the base of said cylinder head.   
     
     
       2. A two stroke diesel engine as defined in claim 1, wherein the distance between the rims of said intake valves and said cylindrical walls is less than the distance between the rims of said intake valves and said extension wall. 
     
     
       3. A two stroke diesel engine as defined in claim 1, wherein said cavity has a second pair of cylindrical walls having a common edge where said walls intersect, said second pair of cylindrical walls being arranged in facing relation to said first pair of cylindrical walls so that the common edge of said second pair of cylindrical walls projects from said extension wall and said fuel injection valve is mounted in this edge portion of said extension wall. 
     
     
       4. A two stroke diesel engine as defined in claim 1, wherein guides having an arc-shaped guide surface are provided on the lower edge of said first pair of cylindrical walls to guide the gas flowing in from the intake valves towards the center of said cavity. 
     
     
       5. A two stroke diesel engine as defined in claim 4, wherein said first pair of cylindrical walls including said guides are constructed of ceramic materials.